To speak for myself, I don't care about ink. I don't even use Apple's pencil. I want to type things into a comment box and be able to search for what I typed later.
This app got started in 2012. It's 2020, and I can't.
Agreed. Searching in non ink should be a piece of cake. I suspect it’s been unimplemented for the same reason that my own request for keyboard shortcuts for bold/underline/change-size has been ignored - they don’t really care about user needs and only do the stuff they like. Which tells you something about the management of the product ...
My apologies for the unimplemented features! Please know it's not because we don't care, we have real-human tech support for even our free users because we desperately care. But we have to focus on the largest demand requests. Fwiw, the biggest request is desktop support, which are in beta now.